The list uses numbers with an 'M' in front. Messier was limited by the objects he could see from France, so the list is incomplete by today's standards. It remains popular because people have used it for centuries and they are familiar with it.

The first edition covered 45 objects numbered M1 to M45. The total list published by Messier finally contained 103 objects, and the list was made up to 110 by modern astronomers working from Messier's notes..[3][4][5]

Almost all the items are either star clusters or nebulae. There are only three galaxies in the first fifty, starting with Andromeda at M31. Individual stars are not listed. The first ten in the list are: